Abstract
BACKGROUND: chronic hepatitis B virus (HBV) infection is a multifactorial disease that can result in serious clinical complications. Host genetic background especially the genes that encode immunologic factors like INF-γ and its receptor (IFN-γ R) are critical in the pathogenesis of infection. OBJECTIVES: The current study aimed to investigate the association between two single nucleotide polymorphisms (SNPs) at positions -611 and -56 within the promoter region of gamma interferon receptor1 gene (IFN-γ R1) and chronic HBV infection. MATERIALS AND METHODS: Genomic DNA from peripheral blood samples of 200 chronically HBV infected patients and 200 healthy blood donors, as controls, were collected and genomic DNA was extracted by phenol-chloroform method and DNA analysis genotype identification was performed by PCR-RFLP. RESULTS: The results indicated that both SNP's frequency had a significant difference in the patient and control groups. At position -56, TT genotype was associated with patient group and P value was 0.002 and at position -611, GG genotype was further observed in control group and P value was 0.006. CONCLUSIONS: Presence of G allele at position -611 within promoter of IFN-γ R1 gene in the enrolled population for the study was related to lower risk of disease, and presence of T allele at position -56 was also related to susceptibility to chronic HBV infection. Men had higher frequency of chronic HBV infection, which might be the result of high risk behavior.